1. Field of the Invention
The present invention relates to an image processing apparatus and an image processing program. More specifically, the present invention relates to an image processing apparatus and an image processing program which renders a 3-dimensional land object such as land object of a virtual golf course.
2. Description of the Prior Art
Conventionally, there is a golf game apparatus in which virtual golf is played on a 3-dimensional virtual golf course. In such a golf game apparatus, it is necessary to accurately and plainly provide a direction and degree of inclination for 3-dimensional configurations forming the golf course for a player. This is because in such a golf game apparatus, similar to golf in the real world, the direction and degree of the configurations are programmed so as to exert an influence on a movement of a ball and thus exert a great influence on a game play. However, a 3-dimensional land object is, if rendered on a display device such as a television monitor and etc., rendered in a 2-dimensional manner, and therefore, it is difficult to recognize the direction and degree of the inclination.
One example of a conventional golf game apparatus is disclosed in a Japanese Letters Patent No. 3410409. The golf game apparatus disclosed in the patent gazette displays guide lines (grid) on a configuration of a golf course in such a manner that luminance of the guide lines is changed depending upon undulations of the configuration.
Furthermore, another example of such a kind of golf game apparatus is well known. In such well-known golf game, a grid is displayed on a configuration of a golf course, and particles moving on the grid are displayed. The particles are displayed in such a manner that at a sharp inclination, the particles run fast, and at a gentle inclination, the particles run slowly.
However, in the golf game apparatus disclosed in the Japanese Letters Patent No. 3410409, since the undulation is represented only by the change of the luminance of the guide lines, in some cases it is difficult to recognize the undulation depending upon the color of the configuration of the golf course as a background. More specifically, a green area and a bunker area are different from each other in colors and it is difficult to recognize the luminance difference between areas having different background colors. Therefore, it is difficult to recognize the direction and degree of the inclination of the course. Furthermore, in a case of displaying a shadow of trees and so on of the golf course for the pursuit of reality, even in the same area, a luminance change caused by the shadow and a luminance change caused by the undulation are mixed with each other, and therefore, the same problem occurs. In addition, there is a problem that due to statically displaying the guide lines without motion, it is difficult to image how the golf ball rolls on the configuration of the golf course.
Furthermore, in the well-known golf game, there is a problem that since the degree of the inclination is provided by the moving speeds of the particles, it is impossible for the player to recognize the difference of the moving speeds without observing the particles closely during a certain amount of time period. Accordingly, in a case of knowing the degrees of the inclinations at a plurality of places on the golf course, it is necessary to recognize the moving speeds at respective places and therefore, it takes a certain amount of time period to recognize the degrees of the inclinations. The problem conspicuously occurs at a place where the moving speed of the particle is late, that is, the degree of the inclination is low.
In addition, it is necessary to display moving objects in addition to the grid. Furthermore, since the 3-dimensional land object, if rendered on the display device such as television monitor and etc., is displayed in a 2-dimensional manner, a depth of the golf course is represented by applying perspective on the display screen. Thus, lengths at the front and the back of the golf course are, even if they have the same distance, different from each other on the display screen, and therefore, even at the same speed, a place at the front and a place at the back are different from each other in speed, and thus, it is difficult to compare the speed of the particles at the front with that at the back. Thus, it is difficult to compare the gradient at the front position with that at the back position. Furthermore, in a case the particles move in the depth direction, it is very difficult to recognize the speed thereof and therefore, it is difficult to recognize the gradient.